Reg Mead and Richard Miles discovered a hoard of 30,000 to 50,000 gold and silver coins, likely buried for more than 2,000 years, inside a large block of clay on the property.

Experts value the buried treasure at $15 million.

Conservator Neil Mahrer of the Jersey Heritage Museum says the discovery is the largest of its kind: "This is the biggest Celtic coin hoard ever found which is tremendously exciting."

"Two thousand years ago the Channel Island — which remains a popular spot to stash large sums of money — was a refuge for tribes fleeing what is now northern France from the invading Roman armies. As the legions of Julius Ceasar drew closer, the treasure is thought to have been buried by a Celtic tribe called the Coriosolitae, in the hope it could be dug up once the danger had passed," the Daily Mailreports.

Earlier this year, Mead and Miles found a much-smaller stash of 61 coins, 60 of them silver. The pair will continue to dig for more.